Radio power supply device



Ap 1930- E. EDELMAN 1,753,921-

RADIO POWER SUPPLY DEVICE Original Filed Jan. 27, 1927 Patented Apr. 8, 1930 UNITED STATES PATENT OFFICE PHILIP E. EDCELMAN, OF CHICAGO, ILLINOIS, ASSIGNOR TO EPHRAIM IBANNING, OF

CHICAGO,

ILLINOIS Original application filed January 27, 1927, Serial No. 163,734. Divided and this application filed September 26, 1927.

An object of the present invention is to improve the operation of a radio power supply device, reduce its bulk and weight as well as cost, provide a unit quiet in operation free from hum noise and undesired heating, which can be shipped ready for use requiring no filling of liquids nor attaching of bulbs, nor re-filling service. This application is divided from my original application S. No. 163,7 34

filed January 27, 1927.

Other objects will presently appear and what I claim as new is more particularly pointed out in the appended claims. I am I describing a preferred form of the invention various forms and modifications of which may be made within the scope of the appended claims.

Radio vacuum tubes requiring direct current for the operation thereof have heretofore been operated either by batteries, combinations of trickle chargers and batteries, wet cells supplied with rectified current thru a choke coil, or combinations requiring special wiring arrangement of the connected radio set. I have sought to provide a unit separate and attachable to any standard radio set without special arrangement or special wiring thereof, which is capable of supplying proper current thereto without requiring any ling 30 or re-filling operations by the user and built up entirely of solid materials. A principal difliculty heretofore has been the filter element which uses a condenser. When constructed as a dielectric condenser this element has a prohibitive cost. When built as'a cell this element has servicing troubles. I provide a new and useful dry solid construction therefor as herein set forth.

I shall now describe a working embodiment of my invention with reference to theaccompanying drawing of which Figure 1 is a schematic diagram.

A transformer 1 has connecting means 2 for attachment to an alternating current supply socket and feeds a full wave rectifier element 1 'thru a carbon pile resistance 3. Rectifier 4 is comprised by polarized sections 7, B, 9, ,10 respectively whereby positive terminal 5- and negative terminal 6 are supplied with rectified current. While any suitable Serial No. 222,170.

rectifier sections may be used, solid type are preferred. Thus each section 7, 8, 9, 10 may comprise as illustrated for section 10, an electrode 11 made from duriron or other suitable material contacting with a solidified chemical conductor13, while a positive electrode 12 made of aluminum or other suitable metal also contacts with the mass 13. Mass 13 is preferably comprised by a solid chemical such as a melted solidified chemical.

A preferred construction is had by immers ing the electrodes 11, 12 closely separated by a fibrous sheet 14 in the molten chemical which is thereafter allowed to cool and crystallize out held by the sheet 1 1 so as to be firmly attached to the electrodes 11 and 12. Thisfibrous sheet can be any suitable fabric material, for example the thin laminated sheet wood fibre material known as cellu: cotton. This cellucotton has the necessary absorbing property while permitting free flow of electricity thru the absorbed crystalline chemical. Such a solidified rectifier section as 10 as described has a uni-directional current conducting 'characteristic probably due to the combine-d effect of a thin film formed on the electrode 12 and the thermic action in the mass 13, 14. Such elements do not appear to deteriorate with use and are preferably permanently scaled up.

Terminals 5, 6 are connected to a filter 15 shown for example as "a single section electrical filter, though additional sections may be employed if desired. Filter 15 comprises two polarized condensers 16, 17 interconnected at their respective positive terminals by a choke coil 18. Choke coil 18 has one core yoke 19 spring hinged at 20 so that the magnetic pull on yoke 19 compresses carbon pile 3....Thereby as the current thru choke coil 18 increases the resistance of carbon pile 3 is decreased and vice versa. If desired relay contacts 27, 28 may also be carried by, yoke 19 for switchin other connections when load current passes thru choke coil 18.

Condenser '16 comprises electrodes 21 polarized positive and 22 electrically negative thereto arranged in a series of layers or as a roll of layers. These electrodes are preferably of ametal such as aluminum though the positive polarized electrode 21 may be of aluminum while the negative electrode 22 is of a different metal inert to the chemical medium 25. These electrodes are constructed of thin sheet metal with large area closely adjacent to each other and se arated by a thin sheet of the chemical medium 25. This chemical medium may comprise a suitable compound crystallized in solid form and held in a thin layer of cellucotton or other suitable fibrous material. The mode of impregnating the absorbent holder 26 isto immerse same in the molten chemical which is allowed to cool and crystallize therein.

A container for the electrodes is indicated by the n uncral 23 so that the electrodes 21, 22 with t e chemical 25 exposed thereto may be sealed from the atmosphere by Vaseline 24. In lieu of "aseline any suitable sealing-medium such as paratfine or parafiine oilvproduet or other petroleum product or like acting substance may be employed. Sueh a condenser besides having large capacity has some internal resistance permitting a slight leakage current, which factor aids in the filterin action. A film appears to form on the positive electrode, making 16 a polarized condenser of relatively high resistance to direct flowing current in one direction and substantially low resistance to alternating current.

Element 17 is similarly constructed but with preferably a larger electrode area'and corresponding lower internal resistance accompanied by an increased capacity due to the lower operating potential caused by the resistance drop in voltage due to the choke coil 18.

In operation, current is supplied to transformer 1 which feeds rectifier 4 thru resistance 3 under control of the magnetic field of choke coil 18. The rectifier output 5, 6 feeds element 16 with its combined capacity and resistance at correct polarity to maintain operating characteristic. The current so rectified and partially stabilized passes from element 16 via-choke coil 18 to combined capacity and resistance element 17 to complete the smoothing thereof. The filtered direct current can then pass to output terminals 29, 30, 31, of which terminal 31 'has a series-resistance 32. The values of the parts maybe selected for either high voltages suitable for".B supply or low voltages suited for A supply and this arrangement is particularly suited for A? supply. For example for A supply the rectifier output at terminals 5, 6 may be 10 volts at 2 amperes. Then choke coil 18 may comprise 600 turns ofNo. 16 enamelled copper wire wound on a core 1" by- 2" cross section of laminated silicon steel, the core being E type with movable yoke 19 as set forth. In such case element 16 may have electrodes formed by alternately adjacent sheets of sheet aluminum 6"x 8" area-spaced by the fibrous sheet carrier 26 of about 1/40 inch thickness carrying the active material 25 held thereby.

Element 17 mayhave similar construction employing electrode sheets in layers. Or if desired the electrodes may be wound in a rolled semi-spiral layer with the active sheets 25, 26 sandwiched therebetween. It is preferable to maintain the transformer 1 energized during use of the device as the unit is immediately available for operating a load which may be for example 10 parallel connected filaments of ten radio vacuum tubes or any similar electrical circuit requiring steady flowlng direct current for operation. The

regulation of resistance 3 is such that Very small no load current is drawn by transformer 1 which lowers the potential applied to elements 16 and 17 when terminals 29, 30 are not loaded. At full load the voltage drop across coil 18 is offset by the lower resistance face to maintain efiicient operation thereof.

Both A and B supply units may be constructed as set forth, in which case relay contacts 27, 28 may be connected in series with the alternating current input to the B unit if so desired.

An alternative mode of construction for the element 16 is to first impregnate the carrier sheet 26 with the active material 25, thereafter assemble same with the electrodes 21, 22, and apply heat briefly thereto to insure intimate contact of the mass 25, 26 with the electrodes 21, 22. The natural property of the chemical 25 used is to adhere to the surfaces of the electrodes 22 and 21 when application is made in the molten state thereof.

If desired the solid type filter 15 may also be electrically operated by means of any suitable type of rectifier on the market.

In the practical working of my invention, it is desirable to leave plug 2 connected to a source of power continuously. The action of regulator 3 under influence of no-load current limits the output of rectifier 4 to very small value sufficient to keep a trickle charge on elements 16, 17, only 100 milliamperes or less being required for this. Under no load, the current drawn from attachment 2 is mainly that required for transformer losses in transformer 1 and negligible in amount. Under load conditions however, regulator 3 tendsto maintain steadyoutput potential at terminals 29 and-30.. t

Each element 16 or 17 exerts a peculiar fil-' ter action in cooperation with im'pedance18 connectedjherebetween as shown,with effect far surpassing that to be'had by aii'ordinary condenser substituted therefor. Elements 16, 17 serve as combined condensers having series'and. shun-t resistance and at the netic force of said choke coil to regulate the same time such resistance is polarized in that there is high impedance to direct current flow in one direction and very low impedance to alternating current flow, accompanied by a forth constituting a novel combination af-' fording apower, supply device of very small bulk and high efliciency;

Claims:

1. As a radio power supply unit the combination of a transformer, means to supply current thereto, a solidified chemical rectifier connected thereto, means to regulate the current supplied to said rectifier, a polarized solidified electrochemical condenser connected to the output of said rectifier, a second polarized solidified electrochemical condenser, a choke coil connecting the positive terchoke coil is decreased, thereby limiting voltage changes applied to said filter circuit when said load is varied.

5. In a filter circuit connected to a rectifier and including a choke coil with capacity connected in shunt thereto, the improvement which consists in providing a movable armature for said choke coil operable in accordance with the influence of the magnetic field set up by current flowing thru said choke coil from said rectifier, whereby in addition to the choking action of said choke coil there is obtained a mechanical motion of said armature, and a variable current consuming element also energized by current flowing thru said rectifier and combined with said armature.

In witness whereof I have hereunto hand this 15th day of August, 1927.

- PHILIP E.'EDELMAN.

V minals of said condensers to form a filter therewith for the output of said retcifier, and

a device combined with said choke coil to operate said regulating means as the output load on said filter is changed.

2. As a radio power supply unit the combination of an alternating current transformer, means to supply current thereto, a full wave rectifier fed thereb thru a resistance, a filter connected to said rectifier and comprising solidified polarized chemical condensers inter-connected by a choke coil, output terminals for said filter, and a device combined with said choke coil to decrease said resistance as the current thru said choke coil increases.

3. A radio power supply unit comprising a transformer, means to supply current thereto, a rectifier for the output of said transformer, a filter for the output of said rectifier, a choke coil included in said filter, and a regulator for said rectifier including an adjustable resistance actuated by the magcurrent supplied by said transformer to said rectifier.

set my I 4. As a radio power supply unit the combination of a transformer, gleansto supply current thereto, a rectifier connected to said transformer, a filter circuit connected to said rectifier and including a load carrying choke coil, and a regulator for said transformer combined with and actauted by said'choke 

